Ashwin Raman's extremely nerdy blog on football

Finding Everton A New Center-Back

Before you read this article, make sure you go through the work of Mark Thompson, who’s (kinda) a one-man army dedicated to figuring out how to use defender stats, and his stuff is arguably the best out there regarding this subject.

Everton now have the heart-winning ex-Hull City and Watford manager Marco Silva in a suit and walking up and down the touchline, and signed Brazilian forward Richarlison from Silva’s last club for a reported fee of £40 million with add-ons (and not the £50 million that everyone seems to be talking about). Things are getting better for Everton, but there is one area in their squad that cries out for strengthening: central defense.

Michael Keane hasn’t been the signing some had hoped he was, Ashley Williams and Phil Jagielka are 33 and 35 respectively, and Mason Holgate isn’t the finished product yet. So in the few days that remain in the Premier League summer transfer window, the Merseyside club should try their best to pick up a new central defender.

There’s a small issue with doing this article with data, though — scouting center-backs with event (on-the-ball) data is hard. Especially if you’re working with the simple stats available on public sites like WhoScored and Squawka.

However, there are ways to approach data-scouting defenders, even if they turn out to be hacky and crude. First, we have to think about Everton’s tactical system under Silva. Do they press high? Considering the way Hull and Watford played under the young Portuguese coach, the answer would be no, and looking for defenders capable of playing in a low block would be the key. Next, looking at easily-quantifiable traits that are ideal for defenders in any system (aerial ability, being able to play long balls well) can do a good job.

So let’s get started.

Step 1: Find me someone who can win the tackles he gets into!

A widespread misconception is that a center-back who makes more tackles or interceptions is a good defender. This isn’t the case, as a high tackle/interception count can be a result of a center-back’s team having to deal with more attacks, a center-back being instructed to actively attempt to win balls, or even the center-back being positioned very badly and out of his defensive line.

Similarly, a high tackle success rate isn’t too indicative of ability either. Sometimes, a player may be instructed to step out of his line and win tackles higher up the pitch, and my hunch is that it’s easier to win a tackle closer to your own goal. Nevertheless, I think a center-back who wins a higher proportion of the tackles he attempts is desirable in a team that defends deep, and tackle success rate is a KPI that we can use in this specific case. Do note that I like to factor in fouls as failed tackles.

I’ve followed a method very similar to the one I tried out eight months ago where I talked about possible options in goal for Liverpool, in which I filter out players who are below average in a certain stat. So filtering out every center-back in Europe’s big-5 leagues who had a tackle success rate below 50% (which very conveniently happens to be the median), we get a list of 154 players. Now onto the next step.

Step 2: Find me someone who can win aerial duels!

Aerial ability is a trait that’s desirable for any defender, and aerial duel win rate can capture this fairly well. Again, I did the same, filtering out anyone with a below-average aerial duel win rate. Now, we’re left with 87 players.

Step 3: Find me someone who can block shots and crosses!

This is one part I’m not totally comfortable with — while having defenders blocking shots and crosses is good for a team like Everton, high block numbers can be a result of a defender’s team being bad at stopping attacks. Anyway, filtering out players with below-average block numbers, we get 43 players. Let’s now move to the final step.

Step 4: Find me someone who can hit it long!

Silva’s Everton is likely to have its center-backs pass long, and having a center-back who can hit those long balls shouldn’t hurt. From the 43 remaining players, I filtered out everyone who hit 3.7 accurate long balls p90 (which is the median) or less, and we have this list, sorted by tackle success rate:

Filtering out everyone unrealistic, too old, in Everton (Phil Jagielka, really?), or from the same league, we get this list:

From the eye test, it looks like Timo Baumgartl is Everton’s best option. Very good at winning tackles, active, a good passer, and as Played Off The Park writes, very good at vertical passing. He along with the more popular Benjamin Pavard and the experienced Holger Badstuber helped create VfB Stuttgart’s impressive defensive record of just 36 goals conceded (only Bayern conceded less).

However, there’s a very good chance that his availability hinges on Pavard potentially leaving Stuttgart, and otherwise, he might be a little out of Everton’s price range. If it’s not him, Everton could look at Florian Lejeune, Niklas Stark, Jannik Vestegaard, Marc-Oliver Kempf, Unai Nunez, or Robin Knoche.

That’s it. This is a largely experimental method, and I don’t genuinely believe it’s of any actual value at a club’s front office, but I hope I’ve done a good job of low-cost center-back scouting, and I hope you enjoyed it.